Mark ParticleTypes as immutable, update tested version

modules/API/src/main/java/com/comphenix/protocol/ProtocolLibrary.java

@@ -39,12 +39,12 @@ public class ProtocolLibrary {
 	/**
 	 * The maximum version ProtocolLib has been tested with.
 	 */
-	public static final String MAXIMUM_MINECRAFT_VERSION = "1.12.2";
+	public static final String MAXIMUM_MINECRAFT_VERSION = "1.13.1";
 
 	/**
-	 * The date (with ISO 8601 or YYYY-MM-DD) when the most recent version (1.12.2) was released.
+	 * The date (with ISO 8601 or YYYY-MM-DD) when the most recent version (1.13.1) was released.
 	 */
-	public static final String MINECRAFT_LAST_RELEASE_DATE = "2017-09-18";
+	public static final String MINECRAFT_LAST_RELEASE_DATE = "2018-08-22";
 
 	/**
 	 * Plugins that are currently incompatible with ProtocolLib.

modules/API/src/main/java/com/comphenix/protocol/reflect/cloning/ImmutableDetector.java

@@ -33,6 +33,7 @@ import java.util.function.Supplier;
 import javax.crypto.SecretKey;
 
 import com.comphenix.protocol.utility.MinecraftReflection;
+import com.comphenix.protocol.utility.MinecraftVersion;
 import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Sets;
 import com.google.common.primitives.Primitives;
@@ -62,9 +63,13 @@ public class ImmutableDetector implements Cloner {
 		add(() -> MinecraftReflection.getMinecraftClass("SoundEffect"));
 		add(MinecraftReflection::getBlockClass);
 		add(MinecraftReflection::getItemClass);
+
+		if (MinecraftVersion.atOrAbove(MinecraftVersion.AQUATIC_UPDATE)) {
+			add(() -> MinecraftReflection.getMinecraftClass("Particle"));
 			add(MinecraftReflection::getFluidTypeClass);
 			add(MinecraftReflection::getParticleTypeClass);
 		}
+	}
 
 	private static void add(Supplier<Class<?>> getClass) {
 		try {